不同烟气组分对Cu_(2)O改性V_(2)O_(5)-MoO_(3)/TiO_(2)脱硝催化剂汞氧化性能的影响  

Effect of different flue gas components on mercury oxidation performance of Cu_(2)O modified V_(2)O_(5)-MoO_(3)/TiO_(2) De-NOx catalyst

作　　者：杨子文 佟莉 左朋莱 宁占武 淡默 梁全明 刘洁玉 YANG Ziwen;TONG Li;ZUO Penglai;NING Zhanwu;DAN Mo;LIANG Quanming;LIU Jieyu(Institute of Urban Safety and Environmental Science,Beijing Academy of Science and Technology,Beijing 100054,China)

机构地区：[1]北京市科学技术研究院城市安全与环境科学研究所,北京100054

出　　处：《环境工程学报》2022年第9期2911-2920,共10页Chinese Journal of Environmental Engineering

基　　金：北京市科学技术研究院北科萌芽计划(BGS202107);河北省省级科技计划(19273706D)。

摘　　要：为提高传统选择性催化还原(Selective Catalytic Reduction,SCR)催化剂的低温汞氧化效率,采用Cu_(2)O对钒钛催化剂进行改性,通过浸渍法制备了系列V_(2)O_(5)-MoO_(3)/TiO_(2)催化剂,利用固定床反应器研究催化剂在不同烟气组分条件下对单质汞的氧化特性。结果表明,在200℃时,2%V_(2)O_(5)-MoO_(3)/TiO_(2)催化剂的Hg0氧化率稳定在99.9%,NO转化率保持在90.9%,具有较好的脱硝协同汞氧化性能。单独的烟气组分如O_(2)、NO、HCl、SO_(2)均有利于Hg0的氧化,而NH_(3)和NO+NH_(3)会抑制Hg0氧化为Hg^(2+)。随着反应温度升高,Hg0氧化率呈现先平稳后降低的趋势,在350℃时,Hg0氧化率仅为64.1%。比表面积测试法(BET),X射线光电子能谱技术(XPS)和H_(2)程序升温还原(H_(2)-TPR)分析表明,Cu_(2)O改性后的V_(2)O_(5)-MoO_(3)/TiO_(2)催化剂,表面Cu和V存在相互作用,使催化剂表面产生不饱和化学键和氧空位,有利于化学吸附氧的增加,从而促进Hg0的氧化。本研究可为提升SCR脱硝催化剂对汞的协同氧化性能提供参考。To improve the mercury oxidation efficiency over conventional traditional Selective Catalytic Reduction(SCR)catalysts at low temperatures,the vanadium-titanium catalysts were modified by Cu_(2)O.A series of Cu_(2)O-V_(2)O_(5)-MoO_(3)/TiO_(2) catalysts were prepared by the impregnation method.The effects of different flue gas components on the oxidation of mercury over the catalysts were investigated by using a fixed-bed reactor.The results suggested that the Hg0 oxidation efficiency was stabilized at 99.9%and the NO conversion efficiency was maintained at 90.9%over 2%V_(2)O_(5)-MoO_(3)/TiO_(2) catalyst at 200℃,which showed a good performance of synergistic De-NOx and mercury oxidation.The individual flue gas components,such as O_(2),NO,HCl,and SO_(2) were conductive to the oxidation of Hg0,while NH_(3) and the coexistence of NO and NH_(3) inhibited the oxidation of Hg0 to Hg^(2+).With the increase of reaction temperature,the Hg0 oxidation efficiency presented a trend of stability and then decrease.The oxidation rate was only 64.1%when the reaction temperature reached 350℃.Specific surface area testing(Brunauer-Emmett-Teller,BET),X-ray photoelectron spectroscopy(XPS)and H_(2) temperature programmed reduction(H_(2)-TPR)analysis demonstrated that when loaded with Cu_(2)O,the interaction between Cu and V existed over the V_(2)O_(5)-MoO_(3)/TiO_(2) catalyst surface produced unsaturated chemical bonds and oxygen vacancies on the surface of the catalyst,which was conductive to the increase of chemisorbed oxygen,thus promoting the oxidation of Hg0.This study can provide a reference for improving the co-oxidation performance of SCR denitrification catalyst for mercury.

关 键 词：Cu_(2)O-V_(2)O_(5)-MoO_(3)/TiO_(2)催化剂 低温选择性催化还原(SCR) Hg0氧化 烟气组分 

分 类 号：X511[环境科学与工程—环境工程]